Java QuickSort StackOverflowError

Hello.I have an error using quicksort and this is a project I have to deliver tomorrow so I hope someone is going to answer tonight.The error occurs for numbers such as 7500 and bigger . Any help ? Thanks!

Exception in thread "main" java.lang.StackOverflowError
at QuickSort.QuickSort(QuickSort.java:45)
at QuickSort.QuickSort(QuickSort.java:46)
at QuickSort.QuickSort(QuickSort.java:46) ...
P.S : SORRY LANGUAGE IS IN ALBANIAN !